Only three cases of Ewing's sarcoma-primitive neuroectodermal tumor (ES-PNET) occurring in the vagina have been previously reported.
A 30-year-old Chinese woman presented with a vaginal mass measuring 5 cm in greatest dimension. The tumor was composed of solid sheets of undifferentiated small round cells with numerous Homer-Wright rosettes. Immunohistochemically, it was positive for CD99, FlI-1 protein, synaptophysin, neuron-specific enolase, vimentin, and S-100 protein. The patient underwent wide local excision of the tumor and subsequent total abdominal hysterectomy with postoperative chemotherapy and radiotherapy. She is disease-free 36 months after the initial surgery.
This is a rare case of ES-PNET occurring in the vagina and the first showing many distinctive Homer-Wright rosettes. A review of literature indicates that vaginal or vulvar ES-PNET affects younger women, and it may have a relatively favorable outcome.